Green Roofs and the Urban Heat Island Effect Jason Jayanty Dr. Stuart Gaffin Dr. Cynthia Rosenzweig

What Are Green Roofs?  Green Roofs are roofs covered by vegetation  Two types of Green Roofs –Intensive – Heavy, expensive; capable of supporting large plants –Extensive – Light-weight patches of shrubbery  Green Roofs are advantageous for –Keeping buildings cooler in the summer and warmer in the winter –Protecting a city from combined sewage overflow during storms –Extend the life of a roof

Extensive Green Roof

Intensive Green Roof (photo by Don Carlson, Carlson Architects)

The Urban Heat Island Effect  The Urban Heat Island Effect refers to the fact that cities can be up to 5-7º C hotter than the surrounding rural areas  This usually happens because… –Anthropogenic heat (Man-Made) –Concrete can absorb a lot of heat –Tall buildings increase overall surface area for heat absorption –Urban Canyon effect

Why New York City?  New York City has 5 times the area of Central Park in roof space (Gaffin et al, 2004)  If even half of these roofs were made green, It would have significant environmental effects. (Rosenzweig et al, 2005)

My Objective  My objective is to confirm LANDSAT surface temperature data at key sites of interest around New York City.  Measure differences between green roofs and black roofs  Measure how quickly surfaces heat up in New York

Observations for July 11, 2005 Observation Site Consistent with Photo Why 1No Possible that the roofs that we couldn’t see hold a lot of heat 2Yes A great deal of vegetation, high tree cover 3No Unknown. Satellite may have been wrong. 4Yes Amount of rocks may have counteracted the vegetation’s effects 5No There was a row of trimmed trees here, and thus without vegetation, heat levels will rise 6aYes Vegetation has an obvious effect on the temperatures here 6bYes Some shade and vegetation, similar to 6a, but on a lesser scale 7Yes highly reflective surfaces and high heat-absorptions of surfaces make this area cool in the day.

Interesting Results So Far Morningside Park113 th Street and Morningside

113 th And Morningside Data

Uris Hall Data

Further Research  Get surface and air measurements over the course of a day  Expand measurements of surface and air temperatures to other regions of high interest